1. Field of the Invention
The present invention relates to a display apparatus for electronic musical instruments, such as a synthesizer, an electronic piano, an electronic organ and a single keyboard, and more particularly, to a display apparatus for electronic musical instruments which displays the levels of tone signals by lighting the associated number of light-emitting elements.
2. Description of the Related Art
Among the known display apparatuses provided in electronic musical instruments, there is a level meter which displays the output signal level of a musical tone. This level meter, provided for each of right and left channels, presents visual confirmation of the tone volumes to help a user adjust the balance of the right and left volumes.
Such a level meter has a line of multiple light-emitting elements. The level of an analog tone signal generated by tone generator means is detected by a known level detector, and the number of light-emitting elements in the level meter that should be lit is controlled in accordance with the detection result. Consequently, the level of a tone signal which is being released as a musical sound can be visually confirmed.
Conventional electronic musical instruments are typically designed so that the tone generator means has a plurality of individual tone parts, such as melody, bass, chord and rhythm. The individual parts are finally mixed into tone signals for two (right and left) channels, or into tone signals for four (front, rear, right and left) channels (these tone signals will be called "output parts"), and the tone signals are then released from loudspeakers.
The level meter is also provided for each output part to display the output signal level of a musical tone for the associated output part.
Particularly, however, electronic musical instruments are often played to feature a predetermined part or to provide the optimal balance for an intended piece of music by adjusting the volumes of individual parts. There is therefore a strong demand to provide a display apparatus for an electronic musical instrument with the ability to present visual confirmation of the volume of the individual tone parts.
As an easy solution to this demand, the level display apparatus may be designed to display the signal level for each individual tone part. But, providing the output part for each individual tone part definitely increases the amount of required hardware, undesirably making the display apparatus expensive.
When the tone volume provided for each part is manipulated or when the display apparatus receives volume information from an automatic playing device, it is not possible to see what level the volume of that part is in.
The tone-ON level at the time a key is depressed (key-On time) of course depends on volume information from the tone volume or an automatic playing device, but also reflects other various factors concerning the strength of the musical tone, such as the velocity and accent information according to the strength of hitting the key. It is therefore difficult for the user to accurately recognize the tone volume level of a presently-playing part to properly control the volume balance between individual tone parts.